聚磷菌的分离鉴定和功能验证
时间:2018-09-18 20:37 来源:毕业论文 作者:毕业论文 点击:次
| 摘要：从实验室驯化的EBPR污泥中成功分离出一株聚磷菌P8。根据其形态学特征、生理生化特性和16S rDNA序列同源性分析结果，初步鉴定为Rhodococcus属内的一个种并命名为Rhodococcus sp. P8。通过摇瓶实验研究了P8菌株生长和磷吸收的最适条件。结果显示P8菌株的最适生长条件为：温度30℃、起始pH为6~8。菌株P8在乙酸浓度为300~2000 mg/L的范围内均可正常生长，同时也可利用丙酸、丁酸、戊酸、乳酸等多种挥发性有机酸作为唯一碳源进行生长。甲苯胺蓝染色结果显示菌株P8胞内可积累poly-P颗粒，在最适条件下菌体磷含量为40.2~51.9 mg/L，是一株有潜力的聚磷菌。摇瓶实验中P8的除磷率可达50~100%，在反应器中的除磷功能有待进一步验证。28360 毕业论文关键词：聚磷菌；强化生物除磷工艺；功能验证；红球菌属 Isolation, Identification and Functional Verification of Phosphorus-accumulating Bacteria Abstract: A polyphosphate accumulating bacterium strain P8 was successfully isolated from EBPR sludge acclimatized in laboratory reactor. It was identified as Rhodococcus sp. according to its cellular morphology, biochemical properties and 16S rDNA sequence homology analysis. The conditions for growth of and phosphorus accumulation by strain P8 were optimized through shake-flask experiments. The optimum growth conditions of P8 strain were 30℃ and initial pH 6~8, respectively. Strain P8 could utilize acetic acid as sole carbon source in the range of concentration of 300~2000 mg/L. In addition to acetic acid, active growth could also be obtained by a variety of volatile fatty acids such as propionic acid, butyric acid, valeric acid and lactic acid. Intracellular polyphosphate had been confirmed by toluidine blue staining and also quite high phosphorus content of 40.2~51.9 mg/L. It could be considered to be a potential polyphosphate accumulating bacterium as indicated by the phosphorus removal rate of 50%~100% in batch shake flask experiments. However, further verification in reactors is still required for its feasibility of phosphorus removal from domestic wastewater. Key words: polyphosphate accumulating bacteria; enhanced biological phosphorus removal process; functional verification; Rhodococcus 目 录 摘要1 关键词1 Abstract1 Key words1 引言1 1 材料与方法2 1.1 实验材料 2 1.2 实验方法 2 1.2.1 菌株的分离与筛选2 1.2.2种子液活化2 1.2.3细菌的形态学特征及生理生化特性的测定2 1.2.4 16S rDNA基因扩增与序列分析2 1.3 分离菌株生长和除磷的最适条件研究2 1.3.1 不同温度对分离菌株生长和除磷的影响2 1.3.2 不同pH对分离菌株生长和除磷的影响2 1.3.3不同乙酸浓度对分离菌株生长和除磷的影响3 1.3.4 不同碳源物质对分离菌株生长和除磷的影响3 1.3.5 poly-P染色方法3 1.3.6 有机酸含量测定3 1.3.7菌体蛋白取样及分析方法3 2结果与分析3 2.1 Rhodococcus sp. P8菌株的形态特征3 2.2 分离菌株的生理生化特性及菌种鉴定4 2.3 Rhodococcus sp. P8菌株生长及除磷的最适条件5 2.3.1 培养温度对Rhodococcus sp. P8生长和除磷率的影响5 2.3.2 培养基初始pH对Rhodococcus sp. P8生长和除磷率的影响6 2.3.3 初始乙酸浓度对Rhodococcus sp. P8生长和除磷率的影响7 2.3.4 碳源种类对Rhodococcus sp. P8生长和除磷率的影响8 3小结与讨论9 致谢9 参考文献9 附录Rhodococcus sp. P8 16S rDNA序列11 聚磷菌的分离鉴定和功能验证 引言 水体富营养化现象日趋严重，严重破坏了人类赖以生存的自然环境，威胁着人类的健康。常规的生化处理工艺效率低，不能从根本上解决问题。近些年，微生物除磷工艺的研究得到了迅速发展，主要有A/O、A2 /O、UCT、五段Bardenpho、Phostrip 等[1-4]。生物除磷通过聚磷菌的超量吸磷实现，其生化机制是在厌氧条件下聚磷菌主要通过水解和释放细胞内的poly-P获得能量同时将废水中的挥发性有机酸转化为PHB存储在胞内，在好氧条件下利用氧气作为电子受体氧化细胞内的PHB，从废水中超量吸磷并以高能聚磷酸键的形式将能量存储在细胞内，排除富磷污泥即可达到除磷目的[5]。 (责任编辑：qin) |